NEUROPATHOLOGICAL STUDIES IN THE BRAINS OF AIDS PATIENTS WITH OPPORTUNISTIC DISEASES

The brains of 70 fatal cases with AIDS were studied by means of immuno histochemistry and in-situ hybridization in a consecutive autopsy seri es (1985 - July 1992). In addition, the neuropathological changes were correlated with the neurological and neuroimaging findings. Opportuni stic infections included toxoplasmosis (15 cases), cytomegalovirus (CM V)-encephalitis (6), progressive multifocal leucoencephalopathy (2) an d fungal infections (3). Malignant lymphomas were found in 7 patients; 6 involved primarily the CNS, one was metastatic. In 14 cases the neu ropathological changes were consistent with HIV encephalitis and HIV l eucoencephalopathy. Non-specific lesions occurred in 31 cases. The cli nical diagnosis in patients with opportunistic diseases (n = 27) diver ged in 15 cases (55%) from the underlying pathology. Toxoplasma gondii , CMV and JC viruses were identified by immunohistochemistry and in-si tu hybridization on serial paraffin sections. In addition, antibodies against lymphocyte subsets, tissue macrophages, the glial fibrillary a cid protein (GFAP) and myelin basic protein were used to characterize the phenotype of cells and to highlight the degree of gliosis and demy elination. Our results show that the distribution and degree of morpho logical changes might be helpful for the differential diagnosis antemo rtem. Since neurological complications may represent the first or sole manifestation of AIDS and risk factors for AIDS are often not known, it should be taken into account that CNS manifestations of AIDS may co ntribute to a sudden and unexpected death or accident. Opportunistic d iseases should be considered as a possible differential diagnosis in c ases mimicking the clinical picture of apoplexia or dementia. Furtherm ore, CNS lesions may be detected postmortem in patients who were not k nown to suffer from Neuro-Aids during life, indicating that CNS involv ement is more widespread than assumed.